Honestly, they do what I want (except the wireless bridging) anyway.
I bought a TP-LINK TL-WA730RE today. Configure it tomorrow; it looks like one of those rare occasions when I'll need to read the instructions.
It means I've now got a router to experiment on (the WRT54G2) so can try out DD-WRT and see if it's worth doing to the much better* N150.
Thanks for the replies.
*so don't want to break it

These days, especially with v24+ it's very hard to brick a router by doing a bad DD-WRT flash.